Actuator systems for oral-based appliances

ABSTRACT

Actuator systems for oral-based appliances utilizing transducers which are attached, adhered, or otherwise embedded into or upon a dental or oral appliance to form a hearing aid assembly. Such oral appliances may be a custom-made device which receives incoming sounds and transmits the processed sounds via a vibrating transducer element. The transducer element may utilize electromagnetic or piezoelectric transducer mechanisms and may be positioned directly along the dentition or along an oral appliance housing in various configurations.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/741,648 filed Apr. 27, 2007 which claims the benefit of priority toU.S. Provisional Patent Application Ser. Nos. 60/809,244 filed May 29,2006 and 60/820,223 filed Jul. 24, 2006, each of which is incorporatedherein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to methods and apparatus for conductingaudio signals as vibrations through teeth or bone structures in and/oraround a mouth. More particularly, the present invention relates tomethods and apparatus for transmitting audio signals via soundconduction through teeth or bone structures in and/or around the mouthsuch that the transmitted signals correlate to auditory signals receivedby a user.

BACKGROUND OF THE INVENTION

Hearing loss affects over 31 million people in the United States (about13% of the population). As a chronic condition, the incidence of hearingimpairment rivals that of heart disease and, like heart disease, theincidence of hearing impairment increases sharply with age.

While the vast majority of those with hearing loss can be helped by awell-fitted, high quality hearing device, only 22% of the total hearingimpaired population own hearing devices. Current products anddistribution methods are not able to satisfy or reach over 20 millionpersons with hearing impairment in the U.S. alone.

Hearing loss adversely affects a person's quality of life andpsychological well-being. Individuals with hearing impairment oftenwithdraw from social interactions to avoid frustrations resulting frominability to understand conversations. Recent studies have shown thathearing impairment causes increased stress levels, reducedself-confidence, reduced sociability and reduced effectiveness in theworkplace.

The human ear generally comprises three regions: the outer ear, themiddle ear, and the inner ear. The outer ear generally comprises theexternal auricle and the ear canal, which is a tubular pathway throughwhich sound reaches the middle ear. The outer ear is separated from themiddle ear by the tympanic membrane (eardrum). The middle ear generallycomprises three small bones, known as the ossicles, which form amechanical conductor from the tympanic membrane to the inner ear.Finally, the inner ear includes the cochlea, which is a fluid-filledstructure that contains a large number of delicate sensory hair cellsthat are connected to the auditory nerve.

Hearing loss can also be classified in terms of being conductive,sensorineural, or a combination of both. Conductive hearing impairmenttypically results from diseases or disorders that limit the transmissionof sound through the middle ear. Most conductive impairments can betreated medically or surgically. Purely conductive hearing lossrepresents a relatively small portion of the total hearing impairedpopulation (estimated at less than 5% of the total hearing impairedpopulation).

Sensorineural hearing losses occur mostly in the inner ear and accountfor the vast majority of hearing impairment (estimated at 90-95% of thetotal hearing impaired population). Sensorineural hearing impairment(sometimes called “nerve loss”) is largely caused by damage to thesensory hair cells inside the cochlea. Sensorineural hearing impairmentoccurs naturally as a result of aging or prolonged exposure to loudmusic and noise. This type of hearing loss cannot be reversed nor can itbe medically or surgically treated; however, the use of properly fittedhearing devices can improve the individual's quality of life.

Conventional hearing devices are the most common devices used to treatmild to severe sensorineural hearing impairment. These are acousticdevices that amplify sound to the tympanic membrane. These devices areindividually customizable to the patient's physical and acousticalcharacteristics over four to six separate visits to an audiologist orhearing instrument specialist. Such devices generally comprise amicrophone, amplifier, battery, and speaker. Recently, hearing devicemanufacturers have increased the sophistication of sound processing,often using digital technology, to provide features such asprogrammability and multi-band compression. Although these devices havebeen miniaturized and are less obtrusive, they are still visible andhave major acoustic limitation.

Industry research has shown that the primary obstacles for notpurchasing a hearing device generally include: a) the stigma associatedwith wearing a hearing device; b) dissenting attitudes on the part ofthe medical profession, particularly ENT physicians; c) product valueissues related to perceived performance problems; d) general lack ofinformation and education at the consumer and physician level; and e)negative word-of-mouth from dissatisfied users.

Other devices such as cochlear implants have been developed for peoplewho have severe to profound hearing loss and are essentially deaf(approximately 2% of the total hearing impaired population). Theelectrode of a cochlear implant is inserted into the inner ear in aninvasive and non-reversible surgery. The electrode electricallystimulates the auditory nerve through an electrode array that providesaudible cues to the user, which are not usually interpreted by the brainas normal sound. Users generally require intensive and extendedcounseling and training following surgery to achieve the expectedbenefit.

Other devices such as electronic middle ear implants generally aresurgically placed within the middle ear of the hearing impaired. Theyare surgically implanted devices with an externally worn component.

The manufacture, fitting and dispensing of hearing devices remain anarcane and inefficient process. Most hearing devices are custommanufactured, fabricated by the manufacturer to fit the ear of eachprospective purchaser. An impression of the ear canal is taken by thedispenser (either an audiologist or licensed hearing instrumentspecialist) and mailed to the manufacturer for interpretation andfabrication of the custom molded rigid plastic casing. Hand-wiredelectronics and transducers (microphone and speaker) are then placedinside the casing, and the final product is shipped back to thedispensing professional after some period of time, typically one to twoweeks.

The time cycle for dispensing a hearing device, from the firstdiagnostic session to the final fine-tuning session, typically spans aperiod over several weeks, such as six to eight weeks, and involvesmultiple visits with the dispenser.

Accordingly, there exists a need for methods and apparatus for receivingaudio signals and processing them to efficiently transmit these signalsvia sound conduction through teeth or bone structures in and/or aroundthe mouth for facilitating the treatment of hearing loss in patients.

SUMMARY OF THE INVENTION

An electronic and transducer device may be attached, adhered, orotherwise embedded into or upon a removable dental or oral appliance toform an assembly which may conduct audio signals to a user via vibratoryconductance through bone for utilization, e.g., as a hearing aidassembly or other audio transmission device. Such a removable oralappliance may be a custom-made device fabricated from a thermal formingprocess utilizing a replicate model of a dental structure obtained byconventional dental impression methods. The electronic and transducerassembly may receive incoming sounds either directly or through areceiver to process and amplify the signals and transmit the processedsounds via a vibrating transducer element coupled to a tooth or otherbone structure, such as the maxillary, mandibular, or palatine bonestructure.

The assembly for transmitting vibrations via at least one tooth maygenerally comprise a housing having a shape which is conformable to atleast a portion of the at least one tooth, and an actuatable transducerdisposed within or upon the housing and in vibratory communication witha surface of the at least one tooth. Moreover, the transducer itself maybe a separate assembly from the electronics and may be positioned alonganother surface of the tooth, such as the occlusal surface, or evenattached to an implanted post or screw embedded into the underlyingbone.

The transducer utilized in the actuator assembly may be anelectromagnetic transducer or a piezoelectric transducer. Piezoelectrictransducers in particular may be used in various configurations due inpart to the various vibrational modes which may be utilized to transmitthe acoustic signals as vibrations through a tooth or teeth. Any numberof transducers may be utilized for particular applications. Forinstance, low voltage multi-layer piezoelectric transducers manufacturedby Morgan Electro Ceramics Ltd. (Wrexham, England) may be utilized forthe applications described herein.

In transmitting the vibrational energy from the transducer to the user,the actuator assembly may be positioned against the tooth or teeth withan impedance matching layer placed therebetween. The impedance matchinglayer may be utilized to improve coupling and optimize the transmissionof vibrational energy from the actuator into the tooth and to optimizethe transmission into the tooth of any reflected vibrations.

One variation of the actuator assembly utilizes a mass coupled to apiezoelectric transducer. Upon application of an electric field, theinduced dipole in the piezoelectric material may align to impart anoscillatory motion upon the mass. The actuator assembly may be coupledto the assembly enclosure via a single anchoring point or a symmetricanchoring feature. The mass may be attached to the composite transducersuch that when the one or more transducers are activated to oscillate, avibrational motion may be imparted to the mass via the anchor such thatthe resulting reaction force is sufficiently transmitted to theunderlying tooth or teeth.

In yet another variation, an actuator assembly may utilize a symmetric(e.g., circularly symmetric) bender transducer assembly having one ormore transducers attached to one another. The one or more transducersmay be the same diameter or a second transducer may have a diameterwhich is less than a diameter of the first transducer. Another variationmay utilize a piezoelectric cap-based design. Such a variation mayutilize a piezoelectric transducer having a thickness and which isconfigured to oscillate in an elongational mode such that the cap may beforced to flex in a direction transverse to the elongational direction,thereby creating the reaction force for transmission into the user'stooth or teeth.

Another variation of an actuator assembly utilizing the force between amagnet contained within the assembly housing and an applied current tocontrol the movement of a mass that may have a permanent magnetsuspended via one or more flexible support members or tethers held inproximity to one or more coils. Coils may be held adjacent to the magnetvia one or more relatively rigid support members and they may carry acurrent which is correlated to the desired auditory signals. When acurrent is passed through the coils in the presence of a magnetic fieldgenerated by magnet, the magnet may vibrate accordingly while suspendedby support members to impart the vibrational reaction force to thetooth.

The span member of the housing assembly is desirably stiff to functionas a platform which allows the transducer assembly to generate asufficient amount of force for transmission into the tooth or teeth.Moreover, to maintain a constant level of output force generated by thetransducer assembly, resonance values of the housing and transducerassemblies may be designed such that they occur outside a desirablefrequency range of interest, e.g., 250 Hz to 10,000 Hz, by optimizingparameters of the housing, such as a thickness of the span member, toalter a resonant frequency of the system. Alternatively, it may bedesirable to place the resonance within the region of interest to moreefficiently drive the tooth.

Turning now to placement of the transducer assembly relative to thetooth or teeth and also with respect to the housing, any number ofconfigurations is available for use. Generally, the housing may becomprised of a single continuous mechanical member configured to haveportions of itself face opposite sides of the tooth or teeth. Theactuator assembly may be effectively pressed against the tooth utilizingthe housing as a foundation and the housing itself may be symmetric ornon-uniform in its configuration. With the transducer positioned withinthe housing, a coupling impedance matching material, such as silicone,may be placed between the piezoelectric transducer and the surface oftooth to optimize conductance of vibrations to the tooth. In othervariations, one or more transducer may be placed along an outer surfaceof the housing and optionally along one or more teeth.

Aside from transducer and housing assemblies which are positioned alongor against one or more teeth, transducer assemblies may be alternativelymounted along a retainer-like structure configured for placementadjacent or along the palate of the user. An arch may extend betweencoupling portions which are configured to extend from the arch forplacement against the lingual surfaces of teeth on opposite sides of theuser's dentition. Rather than utilizing transducer assemblies directlyupon the teeth, the transducer may be removably or permanentlyintegrated along the arch such that elongational vibration of thetransducer conducts the vibrations along the arch for transmissionthrough the coupling portions and into the user's teeth. Alternatively,one or more transducers may be positioned along the arch and actuated todirectly conduct vibrations through the user's palatal bone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the dentition of a patient's teeth and one variationof a hearing aid device which is removably placed upon or against thepatient's tooth or teeth as a removable oral appliance.

FIG. 2A illustrates a perspective view of the lower teeth showing oneexemplary location for placement of the removable oral appliance hearingaid device.

FIG. 2B illustrates another variation of the removable oral appliance inthe form of an appliance which is placed over an entire row of teeth inthe manner of a mouthguard.

FIG. 2C illustrates another variation of the removable oral appliancewhich is supported by an arch.

FIG. 2D illustrates another variation of an oral appliance configured asa mouthguard.

FIG. 3 illustrates a detail perspective view of the oral appliancepositioned upon the patient's teeth utilizable in combination with atransmitting assembly external to the mouth and wearable by the patientin another variation of the device.

FIG. 4 shows an illustrative configuration of one variation of theindividual components of the oral appliance device having an externaltransmitting assembly with a receiving and transducer assembly withinthe mouth.

FIG. 5 shows an illustrative configuration of another variation of thedevice in which the entire assembly is contained by the oral appliancewithin the user's mouth.

FIG. 6 illustrates an example of how multiple oral appliance hearing aidassemblies or transducers may be placed on multiple teeth throughout thepatient's mouth.

FIG. 7 illustrates another variation of a removable oral appliancesupported by an arch and having a microphone unit integrated within thearch.

FIG. 8A illustrates another variation of the removable oral appliancesupported by a connecting member which may be positioned along thelingual or buccal surfaces of a patient's row of teeth.

FIGS. 8B to 8E show examples of various cross-sections of the connectingsupport member of the appliance of FIG. 8A.

FIG. 9 shows yet another variation illustrating at least one microphoneand optionally additional microphone units positioned around the user'smouth and in wireless communication with the electronics and/ortransducer assembly.

FIGS. 10A to 10C illustrate some of the various approaches foroscillating a patient's tooth or teeth (from a single surface, bothsurfaces, or against the occlusal surface, respectively) when conductingaudio signals to the user.

FIGS. 11A to 11C show examples of piezoelectric structures and theirvarious modes of vibration by which they can be utilized, for example,thickness mode, elongational mode, and shear mode, respectively.

FIGS. 12A and 12B show additional examples of composite piezoelectricstructures utilizing unimorph and/or bimorph structures and symmetriccomposite structures, respectively.

FIG. 13 illustrates one example of how an actuator may be positioned tooscillate to deliver acoustic energy through a user's tooth or teeth.

FIG. 14A schematically illustrates an example of an actuator utilizing amass to generate a sufficient actuation force.

FIG. 14B shows some of the various combinations for an electromagnetictransducer assembly utilized with the housing for placement along oragainst a user's dentition.

FIG. 15 schematically illustrates a variation of an actuator utilizing apiezoelectric transducer having a mass coupled thereto.

FIG. 16 schematically illustrates another variation of an actuatorhaving a piezoelectric unimorph or bimorph transducer configured into abeam anchored to the housing.

FIG. 17 schematically illustrates yet another variation utilizing anactuator having a symmetric (e.g., circularly, cylindrically,bilaterally) piezoelectric bender configuration.

FIG. 18 schematically illustrates another variation of an actuatorutilizing a cap-based configuration.

FIG. 19 schematically illustrates another variation of an actuatorutilizing an electromagnetic vibration mechanism.

FIG. 20 illustrates a model of an actuator mounted on an housing.

FIG. 21 illustrates an idealized model of the actuator of FIG. 20.

FIG. 22 shows an example of a plot which may be utilized for determiningan actuator output as a function of a wall thickness of the housing anda thickness of a piezoelectric transducer.

FIGS. 23A and 23B show additional examples of plots which may beutilized for determining actuator output as a function of wall thicknessof the housing and piezoelectric transducer thickness for a housingwhich may be positioned along a proximal surface of a user's tooth.

FIG. 24 shows a cross-sectional representation of an actuator positionedalong a buccal or lingual tooth surface within the housing for effectingactuation of both sides of the tooth through the use of a singleactuator.

FIG. 25 shows a cross-sectional representation of an actuator positionedoutside the housing for effecting two-point actuation.

FIG. 26 shows a cross-sectional representation of two actuatorspositioned along both surfaces of a tooth or teeth within the housingfor effecting two-point actuation.

FIG. 27 shows a cross-sectional representation of two actuatorspositioned outside opposite surfaces of the housing for effectingsymmetric bender actuation.

FIG. 28 shows a variation similar to the variation of FIG. 27 but with ahousing having a span which is thicker relative to the span of FIG. 27.

FIG. 29 shows a cross-sectional representation of an actuator mounteddirectly along a span portion of the housing.

FIG. 30 shows a cross-sectional representation of an actuator mountedadjacent to the span portion of the housing.

FIG. 31 shows a cross-sectional representation of an actuator mountedalong the span portion within the housing directly in contact against anocclusal surface of the tooth or teeth.

FIG. 32 illustrates a top view of an actuator mounted along the buccalsurfaces of multiple teeth.

FIG. 33 illustrates a top view of another variation of an actuator whichis configured to oscillate in the elongational direction to causebending along an arm portion of the housing.

FIG. 34A illustrates a top view of another variation of multipleactuators positioned over multiple teeth.

FIGS. 34B and 34C show side and end views, respectively, of anothervariation for the housing configuration.

FIG. 35 shows a top view of another variation of an actuator positionedalong multiple teeth which utilizes a shearing oscillation.

FIG. 36 shows a top view of another variation of an actuator positionedagainst multiple teeth.

FIG. 37 shows a top view of another variation of an actuator positionedalong multiple teeth within the housing.

FIG. 38 shows a top view of another variation of one or more actuatorspositioned along a housing which is configured to be placed around aposterior surface of a tooth.

FIG. 39 shows a top view of another variation of one or more actuatorswhich are positioned along both buccal and lingual surfaces and whichare connected to one another via wires or members which are positionedbelow the occlusal surfaces.

FIG. 40A shows a top view of an actuator having a mass attached to anarm which extends from the span of the housing.

FIG. 40B shows a cross-sectional view of the actuator and housing ofFIG. 40A.

FIG. 41 shows a top view of an actuator having additional mass elementsattached along the housing.

FIGS. 42A and 42B show top and cross-sectional side views of anothervariation of an actuator having a low impedance reflective layeradjacent to the transducer.

FIGS. 43A and 43B show top and side views of another variation of theactuator configured to be retained against a user's palatal surfacewhile transmitting vibrations through the tooth or teeth.

FIG. 43C shows a side view of another variation of a palatalconfiguration in which the transducer(s) transmits vibrations throughthe palatal surface.

FIG. 44 shows a top view of yet another variation where one or moreactuators may be attached to a retainer.

DETAILED DESCRIPTION OF THE INVENTION

An electronic and transducer device may be attached, adhered, orotherwise embedded into or upon a removable oral appliance or other oraldevice to form an assembly which may conduct audio signals to a user viavibratory conductance through bone for utilization, e.g., as a hearingaid assembly or other audio transmission device. Although described as ahearing aid assembly, the devices and methods herein may be utilized forother auditory treatments or applications and are not limited to use asa hearing aid assembly. Such an oral appliance may be a custom-madedevice fabricated from a thermal forming process utilizing a replicatemodel of a dental structure obtained by conventional dental impressionmethods. The electronic and transducer assembly may receive incomingsounds either directly or through a receiver to process and amplify thesignals and transmit the processed sounds via a vibrating transducerelement coupled to a tooth or other bone structure, such as themaxillary, mandibular, or palatine bone structure.

As shown in FIG. 1, a patient's mouth and dentition 10 is illustratedshowing one possible location for removably attaching hearing aidassembly 14 upon or against at least one tooth, such as a molar 12. Thepatient's tongue TG and palate PL are also illustrated for reference. Anelectronics and/or transducer assembly 16 may be attached, adhered, orotherwise embedded into or upon the assembly 14, as described below infurther detail.

FIG. 2A shows a perspective view of the patient's lower dentitionillustrating the hearing aid assembly 14 comprising a removable oralappliance 18 and the electronics and/or transducer assembly 16positioned along a side surface of the assembly 14. In this variation,oral appliance 18 may be fitted upon two molars 12 within tooth engagingchannel 20 defined by oral appliance 18 for stability upon the patient'steeth, although in other variations, a single molar or tooth may beutilized. Alternatively, more than two molars may be utilized for theoral appliance 18 to be attached upon or over. Moreover, electronicsand/or transducer assembly 16 is shown positioned upon a side surface oforal appliance 18 such that the assembly 16 is aligned along a buccalsurface of the tooth 12; however, other surfaces such as the lingualsurface of the tooth 12 and other positions may also be utilized. Thefigures are illustrative of variations and are not intended to belimiting; accordingly, other configurations and shapes for oralappliance 18 are intended to be included herein.

FIG. 2B shows another variation of a removable oral appliance in theform of an appliance 15 which is placed over an entire row of teeth inthe manner of a mouthguard. In this variation, appliance 15 may beconfigured to cover an entire bottom row of teeth or alternatively anentire upper row of teeth. In additional variations, rather thancovering the entire rows of teeth, a majority of the row of teeth may beinstead be covered by appliance 15. Assembly 16 may be positioned alongone or more portions of the oral appliance 15.

FIG. 2C shows yet another variation of an oral appliance 17 having anarched configuration. In this appliance, one or more tooth retainingportions 21, 23, which in this variation may be placed along the upperrow of teeth, may be supported by an arch 19 which may lie adjacent oralong the palate of the user. As shown, electronics and/or transducerassembly 16 may be positioned along one or more portions of the toothretaining portions 21, 23. Moreover, although the variation shownillustrates an arch 19 which may cover only a portion of the palate ofthe user, other variations may be configured to have an arch whichcovers the entire palate of the user.

FIG. 2D illustrates yet another variation of an oral appliance in theform of a mouthguard or retainer 25 which may be inserted and removedeasily from the user's mouth. Such a mouthguard or retainer 25 may beused in sports where conventional mouthguards are worn; however,mouthguard or retainer 25 having assembly 16 integrated therein may beutilized by persons, hearing impaired or otherwise, who may simply holdthe mouthguard or retainer 25 via grooves or channels 26 between theirteeth for receiving instructions remotely and communicating over adistance.

Generally, the volume of electronics and/or transducer assembly 16 maybe minimized so as to be unobtrusive and as comfortable to the user whenplaced in the mouth. Although the size may be varied, a volume ofassembly 16 may be less than 800 cubic millimeters. This volume is, ofcourse, illustrative and not limiting as size and volume of assembly 16and may be varied accordingly between different users.

Moreover, removable oral appliance 18 may be fabricated from variouspolymeric or a combination of polymeric and metallic materials using anynumber of methods, such as computer-aided machining processes usingcomputer numerical control. (CNC) systems or three-dimensional printingprocesses, e.g., stereolithography apparatus (SLA), selective lasersintering (SLS), and/or other similar processes utilizingthree-dimensional geometry of the patient's dentition, which may beobtained via any number of techniques. Such techniques may include useof scanned dentition using intra-oral scanners such as laser, whitelight, ultrasound, mechanical three-dimensional touch scanners, magneticresonance imaging (MRI), computed tomography (CT), other opticalmethods, etc.

In forming the removable oral appliance 18, the appliance 18 may beoptionally formed such that it is molded to fit over the dentition andat least a portion of the adjacent gingival tissue to inhibit the entryof food, fluids, and other debris into the oral appliance 18 and betweenthe transducer assembly and tooth surface. Moreover, the greater surfacearea of the oral appliance 18 may facilitate the placement andconfiguration of the assembly 16 onto the appliance 18.

Additionally, the removable oral appliance 18 may be optionallyfabricated to have a shrinkage factor such that when placed onto thedentition, oral appliance 18 may be configured to securely grab onto thetooth or teeth as the appliance 18 may have a resulting size slightlysmaller than the scanned tooth or teeth upon which the appliance 18 wasformed. The fitting may result in a secure interference fit between theappliance 18 and underlying dentition.

In one variation, with assembly 14 positioned upon the teeth, as shownin FIG. 3, an extra-buccal transmitter assembly 22 located outside thepatient's mouth may be utilized to receive auditory signals forprocessing and transmission via a wireless signal 24 to the electronicsand/or transducer assembly 16 positioned within the patient's mouth,which may then process and transmit the processed auditory signals viavibratory conductance to the underlying tooth and consequently to thepatient's inner ear.

The transmitter assembly 22, as described in further detail below, maycontain a microphone assembly as well as a transmitter assembly and maybe configured in any number of shapes and forms worn by the user, suchas a watch, necklace, lapel, phone, belt-mounted device, etc.

FIG. 4 illustrates a schematic representation of one variation ofhearing aid assembly 14 utilizing an extra-buccal transmitter assembly22, which may generally comprise microphone or microphone array 30(referred to “microphone 30” for simplicity) for receiving sounds andwhich is electrically connected to processor 32 for processing theauditory signals. Processor 32 may be connected electrically totransmitter 34 for transmitting the processed signals to the electronicsand/or transducer assembly 16 disposed upon or adjacent to the user'steeth. The microphone 30 and processor 32 may be configured to detectand process auditory signals in any practicable range, but may beconfigured in one variation to detect auditory signals ranging from,e.g., 50 Hertz to 20,000 Hertz.

With respect to microphone 30, a variety of various microphone systemsmay be utilized. For instance, microphone 30 may be a digital, analog,and/or directional type microphone. Such various types of microphonesmay be interchangeably configured to be utilized with the assembly, ifso desired. Moreover, various configurations and methods for utilizingmultiple microphones within the user's mouth may also be utilized, asfurther described below.

Power supply 36 may be connected to each of the components intransmitter assembly 22 to provide power thereto. The transmittersignals 24 may be in any wireless form utilizing, e.g., radio frequency,ultrasound, microwave, Blue Tooth® (BLUETOOTH SIG, INC., Bellevue,Wash.), etc. for transmission to assembly 16. Assembly 22 may alsooptionally include one or more input controls 28 that a user maymanipulate to adjust various acoustic parameters of the electronicsand/or transducer assembly 16, such as acoustic focusing, volumecontrol, filtration, muting, frequency optimization, sound adjustments,and tone adjustments, etc.

The signals transmitted 24 by transmitter 34 may be received byelectronics and/or transducer assembly 16 via receiver 38, which may beconnected to an internal processor for additional processing of thereceived signals. The received signals may be communicated to transducer40, which may vibrate correspondingly against a surface of the tooth toconduct the vibratory signals through the tooth and bone andsubsequently to the middle ear to facilitate hearing of the user.Transducer 40 may be configured as any number of different vibratorymechanisms. For instance, in one variation, transducer 40 may be anelectromagnetically actuated transducer. In other variations, transducer40 may be in the form of a piezoelectric crystal having a range ofvibratory frequencies, e.g., between 250 to 15,000 Hz.

Power supply 42 may also be included with assembly 16 to provide powerto the receiver, transducer, and/or processor, if also included.Although power supply 42 may be a simple battery, replaceable orpermanent, other variations may include a power supply 42 which ischarged by inductance via an external charger. Additionally, powersupply 42 may alternatively be charged via direct coupling to analternating current (AC) or direct current (DC) source. Other variationsmay include a power supply 42 which is charged via a mechanicalmechanism, such as an internal pendulum or slidable electricalinductance charger as known in the art, which is actuated via, e.g.,motions of the jaw and/or movement for translating the mechanical motioninto stored electrical energy for charging power supply 42.

In another variation of assembly 16, rather than utilizing anextra-buccal transmitter, hearing aid assembly 50 may be configured asan independent assembly contained entirely within the user's mouth, asshown in FIG. 5. Accordingly, assembly 50 may include at least oneinternal microphone 52 in communication with an on-board processor 54.Internal microphone 52 may comprise any number of different types ofmicrophones, as described below in further detail. At least oneprocessor 54 may be used to process any received auditory signals forfiltering and/or amplifying the signals and transmitting them totransducer 56, which is in vibratory contact against the tooth surface.Power supply 58, as described above, may also be included withinassembly 50 for providing power to each of the components of assembly 50as necessary.

In order to transmit the vibrations corresponding to the receivedauditory signals efficiently and with minimal loss to the tooth orteeth, secure mechanical contact between the transducer and the tooth isideally maintained to ensure efficient vibratory communication.Accordingly, any number of mechanisms may be utilized to maintain thisvibratory communication.

For any of the variations described above, they may be utilized as asingle device or in combination with any other variation herein, aspracticable, to achieve the desired hearing level in the user. Moreover,more than one oral appliance device and electronics and/or transducerassemblies may be utilized at any one time. For example, FIG. 6illustrates one example where multiple transducer assemblies 60, 62, 64,66 may be placed on multiple teeth. Although shown on the lower row ofteeth, multiple assemblies may alternatively be positioned and locatedalong the upper row of teeth or both rows as well. Moreover, each of theassemblies may be configured to transmit vibrations within a uniformfrequency range. Alternatively in other variations, different assembliesmay be configured to vibrate within overlapping or non-overlappingfrequency ranges between each assembly. As mentioned above, eachtransducer 60, 62, 64, 66 can be programmed or preset for a′differentfrequency response such that each transducer may be optimized for adifferent frequency response and/or transmission to deliver a relativelyhigh-fidelity sound to the user.

Moreover, each of the different transducers 60, 62, 64, 66 can also beprogrammed to vibrate in a manner which indicates the directionality ofsound received by the microphone worn by the user. For example,different transducers positioned at different locations within theuser's mouth can vibrate in a specified manner by providing sound orvibrational queues to inform the user which direction a sound wasdetected relative to an orientation of the user, as described in furtherdetail below. For instance, a first transducer located, e.g., on auser's left tooth, can be programmed to vibrate for sound detectedoriginating from the user's left side. Similarly, a second transducerlocated, e.g., on a user's right tooth, can be programmed to vibrate forsound detected originating from the user's right side. Other variationsand queues may be utilized as these examples are intended to beillustrative of potential variations.

FIG. 7 illustrates another variation 70 which utilizes an arch 19connecting one or more tooth retaining portions 21, 23, as describedabove. However, in this variation, the microphone unit 74 may beintegrated within or upon the arch 19 separated from the transducerassembly 72. One or more wires 76 routed through arch 19 mayelectrically connect the microphone unit 74 to the assembly 72.Alternatively, rather than utilizing a wire 76, microphone unit 74 andassembly 72 may be wirelessly coupled to one another, as describedabove.

FIG. 8A shows another variation 80 which utilizes a connecting member 82which may be positioned along the lingual or buccal surfaces of apatient's row of teeth to connect one or more tooth retaining portions21, 23. Connecting member 82 may be fabricated from any number ofnon-toxic materials, such stainless steel, Nickel, Platinum, etc. andaffixed or secured 84, 86 to each respective retaining portions 21, 23.Moreover, connecting member 82 may be shaped to be as non-obtrusive tothe user as possible. Accordingly, connecting member 82 may beconfigured to have a relatively low-profile for placement directlyagainst the lingual or buccal teeth surfaces. The cross-sectional areaof connecting member 82 may be configured in any number of shapes solong as the resulting geometry is non-obtrusive to the user. FIG. 8Billustrates one variation of the cross-sectional area which may beconfigured as a square or rectangle 90. FIG. 8C illustrates anotherconnecting member geometry configured as a semi-circle 92 where the flatportion may be placed against the teeth surfaces. FIGS. 8D and 8Eillustrate other alternative shapes such as an elliptical shape 94 andcircular shape 96. These variations are intended to be illustrative andnot limiting as other shapes and geometries, as practicable, areintended to be included within this disclosure.

In yet another variation for separating the microphone from thetransducer assembly, FIG. 9 illustrates another variation where at leastone microphone 102 (or optionally any number of additional microphones104, 106) may be positioned within the mouth of the user whilephysically separated from the electronics and/or transducer assembly100. In this manner, the one or optionally more microphones 102, 104,106 may be wirelessly or by wire coupled to the electronics and/ortransducer assembly 100 in a manner which attenuates or eliminatesfeedback from the transducer, also described in further detail below.

In utilizing multiple transducers and/or processing units, severalfeatures may be incorporated with the oral appliance(s) to effect anynumber of enhancements to the quality of the conducted vibratory signalsand/or to emulate various perceptual features to the user to correlateauditory signals received by a user for transmitting these signals viasound conduction through teeth or bone structures in and/or around themouth. Examples of various processing methods and systems for simulatingdirectionality as well as for processing algorithms for filtering outundesirable signals, among other features, are shown and described infurther detail in U.S. patent application Ser. No. 11/672,239 filed Feb.7, 2007, which is incorporated herein by reference in its entirety. Thefeatures shown and described may be utilized with any of the variationsdescribed herein and in any number of combinations as practicable.

In transmitting the vibrations generated from auditory signals receivedby the user, the one or more transducers may be positioned relative tothe tooth or teeth as well as relative to the housing itself retainingthe one or more transducers. Generally, an oscillating force 110 may bepresented along a single surface of a user's tooth or teeth TH such thatthe tooth vibrates 112, as shown illustratively in FIG. 10A, andconducts the vibrations through the skull. In another variation, FIG.10B shows how an additional oscillating force 114 may be impartedagainst the tooth TH on an opposite surface from where force 110 isimparted. In this mode, the impedance presented to the actuator isrelatively larger than the impedance presented in FIG. 10A therebypotentially requiring less displacement by the actuator, e.g., about 40dB less relatively. In yet another variation, FIG. 10C shows how anoscillating force 116 may be presented against an occlusal surface ofthe tooth TH. In this variation, the vibrational transmission path isrelatively clear and direct through the tooth TH and to the skull of theuser.

As mentioned above, the transducer utilized in the actuator assembly maybe an electromagnetic transducer or a piezoelectric transducer.Piezoelectric transducers in particular may be used in variousconfigurations due in part to the various vibrational modes which may beutilized to transmit the acoustic signals as vibrations through a toothor teeth. Some of the native vibrational modes of a piezoelectrictransducer which may be utilized in an actuator assembly describedherein are illustrated in FIGS. 11A to 11C.

FIG. 11A shows a representative piezoelectric transducer having dipolesinduced within the molecular or crystal structure of the material whichalign with an electric field applied across the transducer 120. Thisalignment of molecules causes the transducer 120 to change dimensionsand vibrate accordingly in the direction 122. Alternatively, transducer124 may be configured to utilize the dimensional changes in theelongational direction 126 along a length of transducer 124, asindicated in FIG. 11B. In yet another alternative, transducer 128 mayhave an electric field and dipole orientation which results in thetransducer 128 exhibiting shear mode where opposing surfaces oftransducer 128 may vibrate in opposing directions 130. The transducer128 may thus oscillate between its non-deformed configuration and asheared configuration 132, as indicated in FIG. 11C.

In other configurations, the piezoelectric transducer may be utilizedwithin actuator assemblies. These assemblies change the impedance of theactuator and typically generate larger displacements but have relativelylower stiffness and resonance values. For instance, FIG. 12A illustratesan example of a piezoelectric transducer 140 which may be coupled toeither a second transducer or an elastic material 142 to form a benderconfiguration, e.g., unimorph or bimorph configuration. Upon applicationof an electric field, the composite transducer may oscillate in abending or flexing mode 144. In yet another composite modeconfiguration, FIG. 12B illustrates an example of a moonie or cymbaltype transducer which are typically symmetric in shape and which may beutilized in an actuator assembly described herein. Generally, suchcomposite transducers utilize a single layer or multilayer formpiezoelectric transducer 146 which is sandwiched between opposingendcaps 148, 150. Each endcap 148, 150 may form a cavity, such as acrescent-shaped cavity 152, along an inner surface and serves as amechanical transformer for converting and amplifying lateraldisplacements 156 of the transducer 146 into an axial motion 154 of theendcaps 148, 150.

Any number of transducers may be utilized for such particularapplications. For instance, low voltage multi-layer piezoelectrictransducers manufactured by Morgan Electro Ceramics Ltd. (Wrexham,England) may be utilized for the applications described herein.

In transmitting the vibrational energy from the transducer to the user,the actuator assembly 160 may be positioned against the tooth or teethTH with an impedance matching layer 162 placed therebetween, as shown inFIG. 13. The impedance matching layer 162 may be utilized to improvecoupling and optimize the transmission of vibrational energy 166 fromthe actuator 160 into the tooth TH and to optimize the transmission intothe tooth TH of any reflected vibrations. In addition, the couplinglayer will aid in fit and ease of insertion.

One variation of an actuator assembly which may be utilized in thehousing is shown illustratively in FIG. 14, which shows an actuatorassembly 170 enclosing a representative actuator 176 having a mass 172coupled thereto. Actuator 176 may be either an electromagnetic orpiezoelectric transducer depending upon the desired results. Mass 176may be of a size and weight sufficient to generate forces such that anoscillatory motion 174 of mass 172 imparted by actuator 176 leads to areaction force 178 imparted to the tooth TH. Use of a separate mass 172may also be useful in generating a sufficient reaction force 178 even ifa resonance of the assembly itself is in a frequency range of interest.The mass may be comprised of a component fabricated to be the masselement or the mass may be comprised of other components of the systemsuch as, e.g., the associated electronics, battery, charging system,etc.

In configurations utilizing an electromagnetic actuator assembly, thereare a number of various architectures which may be utilized. Forinstance, FIG. 14B shows some of the various combinations for anelectromagnetic transducer assembly utilized with the housing forplacement along or against a user's dentition. The mass 172 utilized maybe either a free mass which may be a separable component aligned withinthe assembly or a tethered mass which is coupled to the housing via amechanical member or mechanism. Aside from the mass, the magnetic fieldmay be configured as either a natural field which follows a natural pathor a directed field which is guided through, e.g., a magnetic circuit.Additionally, the moving mass element may be configured as either apermanent moving magnet or as a current carrying moving coil. Finally,the magnetic field orientation may be varied depending upon theconfiguration of the magnet and mass. Any combination of these elementsmay be utilized for configuring an electromagnetic transducer to achievea desired result, e.g., the combination of a free mass element 172configured as a moving magnet and contained within a directed field maybe utilized.

FIG. 15 illustrates a variation of the actuator assembly which utilizesa mass 172 coupled to a piezoelectric transducer 180. Upon applicationof an electric field 182, the induced dipole 184 in the piezoelectricmaterial may align to impart an oscillatory motion 174 upon mass 172.FIG. 16 shows yet another variation where actuator assembly 170 mayenclose a composite transducer, such as a bending unimorph or bimorphtype transducer having one or more transducer elements 190, 192 coupledtogether. The actuator assembly may be coupled to the assembly enclosure170 via a single anchoring point 196 near or at a first end of thetransducer beam assembly. Alternatively, the actuator assembly may omitanchor 196 entirely and one edge or end of transducer elements 190, 192may be anchored directly to the housing itself. Mass 172 may be attachedto the composite transducer at a second end of the transducer beamassembly also via a single anchoring point 194 such that when the one ormore transducers 190, 192 are activated to oscillate, a vibrationalmotion 174 may be imparted to mass 172 via anchor 194 such that theresulting reaction force 178 is sufficiently transmitted to theunderlying tooth or teeth. The mass 172 secured at anchor 194 may extendaway from or towards anchor 196. It may be advantageous to have the mass172 above or below the beam (e.g., transducers 190, 192) as theresulting moment applied to the beam by the mass 172 during actuationmay develop advantageous moments for various applications. The anchorpoint 194 may also be on the end of the beam (a point down the length ofthe beam from 190).

In yet another variation, FIG. 17 shows an actuator assembly 170utilizing a symmetric (e.g., circularly or bilaterally symmetric) bendertransducer assembly having one or more transducers 200, 202 attached toone another. The one or more transducers 200, 202 may be the samediameter or a second transducer 202 may have a diameter which is lessthan a diameter of the first transducer 200. Mass 172 may be coupled tosecond transducer 202 via anchoring point 204 along its central axis, inwhich case first transducer 200 may be coupled to assembly enclosure 170via multiple anchors 206, 208 or via a circular anchoring element arounda circumference of transducer 200.

Another variation is illustrated in the actuator assembly of FIG. 18,which shows a piezoelectric cap-based design. Such a variation mayutilize a piezoelectric transducer 210 having a thickness 228 and whichis configured to oscillate in an elongational mode 220. Mass 212 havinga thickness and a width 226 may be positioned at a distance 224 awayfrom the transducer surface via a cap member 214 or support membershaving a length 222 and forming an angle, θ, relative to the transducer210. Cap 214 may be fabricated from a metal to be symmetric, e.g.,circularly or bilaterally symmetric, and may define a cavity 216 betweentransducer 210 and cap 214. As piezoelectric transducer 210 is actuatedto oscillate in its elongational direction 220, cap 214 may be forced toflex while vibrating mass 212 in a direction transverse to theelongational direction 220, thereby creating the reaction force fortransmission into the user's tooth or teeth. Because of the flexing ofmass 212 relative to transducer 210 and cap 214, the attachment 218between mass 212 and cap 214 may be configured into a joint to allow forthe relative movement. Any number of pivoting or bending mechanisms maybe utilized, e.g., living hinges, silicone glue joints, etc.Alternatively, the device may be configured such that the mass 212 isconnected to the piezoelectric transducer 210 and the reaction force istransmitted to the load through the cap 214 itself. Additionally, thedevice may have a top and a bottom cap which are placed on oppositesides of the transducer 210. In this variation, the mass 212 may beattached to either top or bottom cap while the force is transmitted tothe load through the remaining cap.

FIG. 19 shows another variation of an actuator assembly utilizing theforce between a magnet contained within the assembly housing 170 and anapplied current to control the movement of a mass. Magnet 230 may be apermanent magnet suspended via one or more flexible support members 232held in proximity to one or more coils 238. Separate coils may bepositioned on either side of magnet 230 such that the device issymmetric with respect to the magnet 230. Such extra coils may improvethe force output linearity of the device. Moreover, magnet 230 mayadditionally function as the mass or a separate mass element may beattached to magnet 230. Coils 238 may be held adjacent to magnet 230 viaone or more relatively rigid support members 236 and they may carry acurrent 240, 242 which is correlated to the received and processedauditory signals. When a current is passed through the coils 238 in thepresence of a magnetic field 234 generated by magnet 230, magnet 230 mayvibrate accordingly while suspended by support members 232 to impart thevibrational reaction force to the tooth TH.

Regardless of the specific transducer design, the resulting functionaltransmitted output level is desirably constant over a specifiedfrequency range which is below uncomfortable loudness and vibrationlevels over the entire frequency range.

In determining the parameters for the desired amount of deflectiongenerated by the transducer assembly as well as for design parametersfor the housing assembly, the entire system 260 may be modeled as springmembers coupled in series. As illustrated in FIG. 20, half of the system260 divided along the symmetrical line 262 may be modeled as an armmember 264 and bottom or span member 266. Transducer assembly 268 andits generated vibrational force 270 may be coupled along arm member 264,in this particular example. Although each member 264, 266 may have itsown compliance value, the entire system compliance may be determined bya sum of the individual compliance values.

FIG. 21 illustrates a schematic representation 272 of a transducer andhousing assembly where the inductor-capacitor circuit 274 represents theequivalent value from the tooth TH, circuit 276 represents theequivalent value from arm member 264, circuit 278 represents theequivalent value from span member 266, and schematic 280 represents thecoupled area between the arm member 264 and tooth TH and the amount oftransducer deflection or throw 282. The total throw 282 of thetransducer 268 may be divided between the tooth TH and the housing wherethe softer of the two deflects the most. The amount of force 270transmitted by the transducer 268 may be determined by the stiffness ofthe tooth and the amount of displacement at the tooth TH. Thus, thesofter the housing material relative to the tooth TH, the lessdisplacement may be transmitted thereby such that the amount of throw282 that should be increased.

The span member 266 of the housing assembly is desirably stiff tofunction as a platform which allows the transducer assembly 268 togenerate a sufficient amount of force for transmission into the tooth orteeth TH. Moreover, although any number of transducer designs may beutilized, as shown herein, multilayer piezoelectric transducers may beparticularly effective in multiplying the voltage output. Moreover, tomaintain a constant level of output force generated by the transducerassembly, resonance values of the housing and transducer assemblies maybe designed such that they occur outside a desirable frequency range ofinterest, e.g., 250 Hz to 10,000 Hz, by optimizing parameters of thehousing, such as a thickness of the span member 266, to alter a resonantfrequency of the system.

Plot 290 of FIG. 22 illustrates in one example the relationship of thedB output as a function of the thickness of the housing and a thicknessof the piezoelectric transducer material. The contour lines indicateequal dB output values where line 292 represents optimal output valuesfor a given device size. Accordingly, for a given thickness of apiezoelectric transducer material, e.g., 2 mm thick, increases in thethickness of the housing material leads to nominal increases in outputlevels whereas increases in the stiffness of the span member may lead torelatively greater output values.

FIGS. 23A and 23B show plots 300 and 304, respectively, which alsoillustrate the relationship of dB output as a function of housingthickness and piezoelectric transducer material thickness for aparticular variation of the housing having a span member configured forplacement along a posterior surface of a tooth, as shown in FIG. 38. Forthese particular examples, line 302 in plot 300 and line 306 in plot 304both represent optimal output values for a given device size where athickness of the span in FIG. 23A is 2.25 mm and a thickness of the spanin FIG. 23B is 7.5 mm. These illustrations are intended merely asexamples of the relational correlation between the various parametersand the relative outputs for given span thicknesses. Moreover, thesevalues are not intended to be limiting in any manner and are merelyexemplary.

Turning now to placement of the transducer assembly relative to thetooth or teeth TH and also with respect to the housing, any number ofconfigurations is available for use. For example, FIG. 24 shows oneexample of a piezoelectric transducer 312 positioned within a housing310 for direct placement against the tooth or teeth TH. Housing 310 mayhave a thickness of, e.g., 0.4 mm with a span member having a length,e.g., of 10 mm. The housing 310 may have a length of 7 mm for placementalong one or more teeth TH. Furthermore, the piezoelectric transducer312 may have a height of 7 to 9 mm. Of course, these values are given asexamples and are subject to change depending variables such as thedesired vibrational conductance as well as variables in a user'sparticular dentition, among other factors.

Generally, the housing 310 may be comprised of a single continuousmechanical member configured to have portions of itself face oppositesides of the tooth or teeth TH. The actuator assembly may be effectivelypressed against the tooth TH utilizing the housing as a foundation andthe housing 310 itself may be symmetric or non-uniform in itsconfiguration. In one example, the arm portions of the housing may beplaced along opposing surfaces of at least one tooth, e.g., along therespective lingual and buccal surfaces of the tooth or teeth. The armportions may be coupled to one another via the span member such that thearms are urged or otherwise biased towards one another such that theypress against their respective tooth surfaces. A housing with arelatively soft material may utilize a configuration and stiffness wherea first resonant frequency mode of the span portion is below a region ofinterest while a first resonant frequency mode of the arm portion iswithin, near the upper range, or above the upper end of the frequencyrange of interest, as described above. As the transducer is driven pastthe first mode of the span portion, the span may appear to becomerelatively stiffer, thereby increase the force output of the system.Alternatively, additional mass can be added provided that the mass isadded in such a way to ensure that the resonance of the arm memberremains at the upper end of the frequency range of interest.

With transducer 312 positioned within housing 310, a coupling impedancematching material 314, such as silicone, may be placed betweenpiezoelectric transducer 312 and the surface of tooth TH to optimizeconductance of vibrations 316 to the tooth TH. In this particulardesign, the arm members of housing 310 may be both driven 318 to flexrelative to the tooth TH and may facilitate transmission of vibrations.FIG. 25 shows another variation also utilizing a single piezoelectrictransducer 312 positioned along an outer surface of the housing 310. Inthis example, the piezoelectric element 312 drives the housing 310 in aunimorph-like manner pushing against the housing 310 and squeezing thetooth TH from both sides. The vibratory motion of transducer 312 may betransmitted 316, 320 by both arm members into opposing surfaces of toothTH rather than directly against a single surface of the tooth TH.

FIG. 26 shows another variation utilizing two-point actuation where atleast two transducers 312, 322 may both be positioned within housing 310directly against opposite surfaces of tooth TH. In this variation, firsttransducer 312 may vibrate 316 along a first surface of tooth TH andsecond transducer 322 may vibrate 320 along a second surface of toothTH. Moreover, both transducers 312, 322 may be configured to vibratesimultaneously or out-of-phase, depending upon the desired results.

FIG. 27 shows another variation utilizing two-point actuation where atleast two transducers 312, 322 are positioned along outer surfaces ofhousing assembly 310. In this example, the respective vibrations 316,320 may be transmitted through the housing 310, through couplingmaterial 314, and into tooth TH. FIG. 28 shows an example similar to thevariation in FIG. 27 where transducers 312, 322 may be mounted along anouter surface of housing 330 on opposite sides of tooth TH, but spanmember 332 connecting both arm members of housing 330 is thicker, e.g.,twice as thick as the span member of housing 310 of FIG. 27. Theincreased thickness of span member 332 may result in a relativelystiffer span member 332 which increases an amplitude of the transmittedvibrations 316, 320.

Other symmetric bender actuation configurations are illustrated, forexample, in FIG. 29 which shows transducer 340 positioned along an outersurface of the span portion of housing 310. Actuation of transducer 340may not only oscillate the arm members of the housing 310, but maytransmit the vibrations through an occlusal surface of tooth TH. FIG. 30illustrates a similar variation where transducer 340 is positioned alongthe span portion of housing 344 separated by a gap 342 betweentransducer 340 and the remainder of housing 344. And FIG. 31 illustratesyet another variation where transducer 340 is positioned within housing310 for placement directly against the occlusal surface of tooth TH suchthat vibrations 346 from transducer 340 are transmitted directly intothe tooth TH.

Some of the various configurations for actuator placement relative tothe tooth and/or housing have been illustrated. Additional variationsfor positioning the housing and vibrational mechanisms over multipleteeth are now illustrated. Turning now to FIG. 32, a top view ofactuator 350 is shown mounted along the buccal surfaces of multipleteeth TH. The transducer 350 may be mounted between an arm member ofhousing 310 and the surface of teeth TH with the coupling material 314placed therebetween. Although housing 310 may extend along the length ofa single tooth, transducer 350 may extend along several teeth.

FIG. 33 shows another variation where transducer 354 may be placed alongan outer surface of an arm member 352 of housing 310 and having an armmember which extends over several teeth. Transducer 354 may beconfigured to vibrate along a longitudinal direction 345 such that thetransducer pushes and pulls causing bending 316 in the elongate armmember 352 and pushing on the teeth TH.

FIG. 34A shows yet another example where at least two housing assembliesmay be utilized on both sides of a patient's dentition 10. The firsthousing may utilize a transducer 360 positioned along the housing andvibrating 362 against the teeth and the second housing may similarlyutilize a transducer 364 also vibrating 366 against the teeth. FIG. 34Bshows a side view of an example of the housing 310 along a lingualsurface of the teeth TH where a portion of the teeth are utilized forsecuring the housing. FIG. 34C shows a partial cross-sectional side viewillustrating the transducer 364 secured within the housing 310 fordirect placement against the teeth TH. Any of the various transducer andhousing configurations shown herein may be utilized in either the firstand/or second housing configurations.

FIG. 35 shows yet another variation of an assembly utilizing atransducer 370 configured to vibrate in a shear mode where opposingsurfaces of the transducer 370 vibrate in opposing directions 372. Theshearing motion 372 is applied to the teeth through the impedancematching layer 314 and directly generates forces in the tooth. FIG. 36shows another variation where transducer 374 is configured to vibrate ina transverse direction 376 while contained within a housing 310 which isstiffened. Because housing 310 is relatively stiffer than otherconfigurations, housing 310 is less prone to bending and flexing suchthat the vibrations 376 may be transferred into each underlying toothcontacted by coupling material 314 and transducer 374. FIG. 37 alsoshows another configuration utilizing transducer 374 having anadditional mass 378 which may be accelerated by transducer 374 togenerate a force sufficient for conducting into the underlying teeth.

Another alternative configuration is shown in FIG. 38, which illustratesa housing 380 having a span member 388 which is positioned around and incontact against a posterior surface of a tooth. One or more transducerassemblies 382, 384 may be positioned along the arm members of housing380 for oscillating either against an outer surface of housing 380, asshown, or for direct placement against the lingual and buccal surfacesof the tooth. Coupling material 386 may be placed between housing 380and the underlying tooth to facilitate transmission of vibrations andease of insertion of the oral appliance. Examples of design parametersfor this particular configuration of housing 380 are shown in FIGS. 23Aand 23B, as described above.

FIG. 39 shows yet another variation where the arm portions of housing390 may be placed along both lingual and buccal surfaces of a toothwhile connected to one another via span members which are configured aswires 394. The wires 394 may be routed such that they are positionedbelow the occlusal surfaces of the teeth or between the teeth so as tobe minimally obtrusive. Moreover, transducer assemblies 382, 384 may bepositioned along the outer surfaces of housing 390, as shown, or theymay be placed directly against the tooth surfaces. In either case, acoupling material 392 may be placed against the tooth to facilitatetransmission of vibrations therethrough.

FIGS. 40A and 40B show top and cross-sectional views, respectively, of ahousing assembly 400 having a mass 404 attached to an arm member 408which extends from the span 406 of the housing 400. The piezoelectrictransducer 402, which is attached to member 403 thereby becoming anactuator, acts, in concert with member 403 as a unimorph to pushdirectly on the underlying tooth or teeth TH. The actuator is attachedto the housing 400 at its two ends points. This arrangement ofattachment allows the actuator to actuate with necessitating motion ofthe housing 400 and mass 404. The system is such that the mass 404 andhousing 400 resonance is relatively low. Hence, while very pliable andsoft on a human scale, it may provide a sufficiently solid foundation inthe frequency range of interest to allow the unimorph to generate largeforces on the tooth TH during actuation. While a unimorph is depicted, acap device or any of the other transducer architectures described hereinmay be used in place of the unimorph transducer. FIG. 41 shows anothervariation which also utilizes additional mass elements 410, 412 whichare attached to an outer surface of housing 400 adjacent to transducer402 rather than along a separately movable arm member 408. Althoughshown with two mass elements 410, 412, additional masses may be utilizeddepending upon the desired transmission results.

FIGS. 42A and 42B show top and cross-sectional views, respectively, ofyet another variation utilizing a housing 400 and piezoelectrictransducer 402 coupled directly to a tooth surface. In this variation,arm member 408 extends separately from span member 406, as above, butalso includes a low impedance reflective layer 420 surroundingtransducer 402 and also between transducer 402 and arm member 408. Thereflective layer 420 may be comprised of a material, such as silicone,which acts to reflect vibrational energy transmitted from transducer 402and retransmit the energy back into tooth TH.

Aside from transducer and housing assemblies which are positioned alongor against one or more teeth, transducer assemblies may be alternativelymounted along a retainer-like structure configured for placementadjacent or along the palate of the user. Similar to other variationsdescribed above, arch 430 may extend between coupling portions 436 whichare configured to extend from the arch 430 for placement against thelingual surfaces of teeth TH on opposite sides of the user's dentition,as illustrated in FIG. 43A. Rather than utilizing transducer assembliesdirectly upon the teeth, transducer 432 may be removably or permanentlyintegrated along arch 430 such that elongational vibration 434 of thetransducer 432 conducts the vibrations along arch 430 for transmission438 through coupling portions 436 and into the user's teeth TH, as shownin the partial cross-sectional side view of FIG. 43B. Alternatively, oneor more transducers 440 may be positioned along arch 430 and actuated todirectly conduct vibrations 442 through the user's palatal bone, asshown in FIG. 43C. A layer of polyvinylidene fluoride (PVDF), forexample, may generate the desired vibrations.

FIG. 44 shows yet another variation similar to the configuration shownabove in FIG. 8A which utilizes connecting member 82 which may bepositioned along the lingual or buccal surfaces of a patient's row ofteeth to connect a first tooth retaining portion 450 and a second toothretaining portion 452. One or more transducer assemblies 454, 456 may beintegrated within the first retaining portion 450 to align along thebuccal and lingual surfaces of one or more teeth. Similarly, one or moretransducer assemblies 458, 460 may also be integrated within the secondretaining portion 452 to align along the lingual and buccal surfaces ofone or more teeth. Such a configuration may be particularly useful inincorporating a number of transducers positioned at various locationsalong the dentition, as described in further detail in U.S. patentapplication Ser. No. 11/672,239, which has been incorporated byreference above.

The applications of the devices and methods discussed above are notlimited to the treatment of hearing loss but may include any number offurther treatment applications. Moreover, such devices and methods maybe applied to other treatment sites within the body. Modification of theabove-described assemblies and methods for carrying out the invention,combinations between different variations as practicable, and variationsof aspects of the invention that are obvious to those of skill in theart are intended to be within the scope of the claims.

1. An apparatus for conducting vibrations via at least one tooth,comprising: a housing having a shape which is conformable to at least aportion of the at least one tooth; a transducer disposed within or uponthe housing and in vibratory communication with a surface of the atleast one tooth; and a mass element coupled to the transducer andmovable relative to the housing whereby movement of the mass elementgenerates a force transmittable through the surface of the at least onetooth.